JP5777049B2 - Wave measuring method and wave measuring system using ultrasonic waves - Google Patents

Description

  The present invention relates to a wave measuring method and a wave measuring system using ultrasonic waves.

When performing steady wave observations, that is, when measuring waves, it is common to use a hydraulic wave height meter that measures pressure fluctuations at the sea floor.
By the way, it is good to use this water pressure type altimeter in shallow water, but when used in a deep water, the movement of water particles due to sea surface waves does not reach the sea floor. The sensitivity of the type wave height meter becomes dull.

For this reason, when this hydraulic wave height meter is used, an observation waveform that has passed through a low-pass filter is obtained, and the accuracy and reliability of the observation data must be reduced.
On the other hand, the ultrasonic wave height meter is superior to the hydraulic wave height meter in that the waveform of the sea surface can be obtained directly, and is currently widely used in coastal areas throughout the country.

  This ultrasonic wave height meter emits an ultrasonic pulse of a sharp beam toward the sea surface from a transmitter / receiver installed on the seabed, receives a reflected wave from the sea surface, and the round-trip propagation time of this ultrasonic pulse ( The sea level waves are observed by continuously recording (corresponding to the sea level). (See Non-Patent Document 1)

"Commentary on analysis and utilization of coastal wave and oceanographic observation data (pages 3 to 4)" Coastal Development Technology Research Center, August 2000

  According to the above-mentioned conventional ultrasonic wave height meter, the ultrasonic wave is transmitted from the transmitter / receiver installed on the seabed toward the sea surface and the reflected wave from the sea surface is received. The sea surface is disturbed along with the breaking of the waves, and a large amount of bubbles are entrained to absorb and scatter the ultrasonic waves. As a result, there is a problem that the measurement accuracy is lowered and in some cases measurement is impossible.

  Therefore, an object of the present invention is to provide a wave measuring method and a wave measuring system using ultrasonic waves that can be measured accurately even when the waves are high.

In order to solve the above-described problem, the wave measuring method using the first ultrasonic wave according to the present invention detects a wave height in a predetermined sea area by detecting a change in a floating body suspended and moored on the sea surface. Measuring method,
At least three marine structures and seabed or ocean floor near below the floating bodies are not be affected by waves than the floating body is larger than the floating while being suspended, anchored to the sea surface in a predetermined sea area A first ultrasonic receiver serving as a reference provided below the sea surface of the marine structure and an observation second provided below the sea surface of the floating body are transmitted from the ultrasonic transmitter disposed. Received with an ultrasonic receiver,
The distance between the ultrasonic transmitter and each ultrasonic receiver is determined based on the propagation time from the transmission of the ultrasonic wave transmitted from the ultrasonic transmitter to the reception, and the difference between these two distance data. Seeking
High-pass filter processing is performed on the difference between the two distance data obtained above to extract a short period fluctuation component,
The above-mentioned formula is extracted in which each relative displacement amount on the three-dimensional coordinate axis between the two ultrasonic receivers having coefficients of the azimuth angle and the depression angle of the first ultrasonic receiver with respect to the ultrasonic transmitter is an unknown. A ternary linear equation that is equal to the short-period fluctuation component is created for each ultrasonic transmitter, and the ternary simultaneous equation is solved to obtain at least the displacement in the height direction of the short-period fluctuation component. This is how to get the height.

The wave measurement system using ultrasonic waves according to the first aspect of the present invention is a wave measurement system that measures the height of a wave in a predetermined sea area by detecting a change in a floating body suspended and moored on the sea surface. ,
While being suspended, anchored to the sea surface in a predetermined sea area is larger than the floating first to be provided with reference respectively below has been offshore structures and the floating so as not to be affected by wave than the floating An ultrasonic receiver and a second ultrasonic receiver for observation;
An ultrasonic transmitter disposed at least at three locations on or near the seabed below the offshore structure and floating body;
Waves that measure the wave height by determining the distance between the ultrasonic transmitter and each ultrasonic receiver based on the propagation time from the transmission of the ultrasonic wave transmitted from the ultrasonic transmitter to reception. A measuring device,
The above wave measuring device
A distance calculation unit for determining a distance between the ultrasonic transmitter and each ultrasonic receiver based on a propagation time from transmission of the ultrasonic wave transmitted from the ultrasonic transmitter to reception thereof, and the distance calculation unit A difference calculation unit for obtaining a difference between the two distance data obtained in step 1, a short cycle fluctuation component extracting unit for extracting a short cycle fluctuation component by performing a high-pass filter process on the difference between the two distance data obtained by the difference calculation unit, and The above-mentioned formula is extracted in which each relative displacement amount on the three-dimensional coordinate axis between the two ultrasonic receivers having coefficients of the azimuth angle and the depression angle of the first ultrasonic receiver with respect to the ultrasonic transmitter is an unknown. A ternary linear equation that is equal to the short-period fluctuation component is created for each ultrasonic transmitter, and the ternary simultaneous equation is solved to obtain at least the displacement in the height direction of the short-period fluctuation component. Those constructed from short-period fluctuation component calculation section for obtaining a of.

The second wave measurement method using ultrasonic waves according to the present invention is a wave measurement method for measuring the height of a wave in a predetermined sea area by detecting a change in a floating body suspended or moored on the sea surface. ,
While being suspended, anchored to the sea surface in a predetermined sea area is larger than the floating first be provided with reference respectively under sea surface has been offshore structures and the floating so as not to be affected by wave than the floating An ultrasonic wave is transmitted into the sea from one ultrasonic transmitter / receiver and a second ultrasonic transmitter / receiver for observation, and the ultrasonic waves from the wave repeaters arranged at least at three locations near or below the bottom of the sea Received with an ultrasonic transceiver,
The distance between the ultrasonic repeater and each ultrasonic transmitter / receiver is determined based on the round-trip propagation time from the transmission of the ultrasonic wave transmitted from the ultrasonic transmitter / receiver to the reception thereof, and the difference between these two distance data Seeking
High-pass filter processing is performed on the difference between the two distance data obtained above to extract a short period fluctuation component,
An expression in which the relative displacements on the three-dimensional coordinate axis between the two ultrasonic receivers with the coefficients of the azimuth angle and the depression angle of the first ultrasonic transmitter / receiver as a coefficient is an unknown is extracted. Create a ternary linear equation equal to the periodic fluctuation component for each sonic repeater, and solve this ternary linear equation to obtain at least the displacement in the height direction of the short periodic fluctuation component to determine the wave height Is the way to get.

The wave measurement system using the second ultrasonic wave according to the present invention is a wave measurement system for measuring the wave height in a predetermined sea area by detecting a change of a floating body suspended and moored on the sea surface. ,
While being suspended, anchored to the sea surface in a predetermined sea area is larger than the floating first to be provided with reference respectively below has been offshore structures and the floating so as not to be affected by wave than the floating An ultrasonic transceiver and a second ultrasonic transceiver for observation;
Acoustic repeaters disposed at least at three locations on or near the bottom of the ocean structure and floating body;
Waves for measuring the wave height by determining the distance between the sound wave repeater and each of the ultrasonic wave transmitters / receivers based on the round-trip propagation time from transmission of the ultrasonic wave transmitted from the ultrasonic wave transmitter / receiver to reception. A measuring device,
The above wave measuring device
A distance calculation unit for determining a distance between the sound wave repeater and each of the ultrasonic transmitters / receivers based on a round-trip propagation time from transmission of the ultrasonic wave transmitted from the ultrasonic transmitter / receiver to reception thereof, and the distance calculation unit The difference calculation unit for calculating the difference between the two distance data obtained in step 1, and the short cycle fluctuation component extracting unit for extracting the short period fluctuation component by performing high-pass filter processing on the difference between the two distance data obtained by the difference calculation unit. , And the above-mentioned formulas using the relative displacements on the three-dimensional coordinate axis between the two ultrasonic receivers with the azimuth angle and the depression angle of the first ultrasonic transmitter / receiver as the coefficients relative to the sound wave repeater as the coefficients are extracted as described above. A ternary linear equation that is equal to the short-period fluctuation component is created for each sonic repeater, and at least the height of the short-period fluctuation component is solved by solving the ternary simultaneous equation. Those constructed from short-period fluctuation component calculation section for obtaining a wave height seeking of displacement.

The third wave measurement method using ultrasonic waves according to the present invention is a wave measurement method for measuring the height of a wave in a predetermined sea area by detecting a change in a floating body suspended and moored on the sea surface. ,
While being suspended, anchored to the sea surface in a predetermined sea area is larger than the floating first be provided with reference respectively under sea surface has been offshore structures and the floating so as not to be affected by wave than the floating Sending ultrasonic waves into the sea from 1 ultrasonic transceiver and 2nd ultrasonic transceiver for observation,
The ultrasonic waves and relay times relayed by the ultrasonic wave relays arranged at least at three locations on the seabed or near the seabed below these ultrasonic wave transceivers are received by the ultrasonic wave transmitters and received from the ultrasonic wave relays. The distance between the sonic repeater and each ultrasonic transmitter / receiver is determined based on the propagation time of each, and the difference between these two distance data is determined,
High-pass filter processing is performed on the difference between the two distance data obtained above to extract a short period fluctuation component,
An expression in which the relative displacements on the three-dimensional coordinate axis between the two ultrasonic receivers with the coefficients of the azimuth angle and the depression angle of the first ultrasonic transmitter / receiver as a coefficient is an unknown is extracted. Create a ternary linear equation equal to the periodic fluctuation component for each sonic repeater, and solve this ternary linear equation to obtain at least the displacement in the height direction of the short periodic fluctuation component to determine the wave height Is the way to get.

The wave measurement system using ultrasonic waves according to the third aspect of the present invention is a wave measurement system that measures the wave height in a predetermined sea area by detecting a change in a floating body suspended and moored on the sea surface. ,
A marine structure that is floated and moored on the surface of a predetermined sea area and is larger than the floating body so that it is less affected by waves than the floating body. An ultrasonic transceiver and a second ultrasonic transceiver for observation;
A sonic repeater that is disposed at least at three locations on the seabed or near the seafloor below the offshore structure and floating body and relays the ultrasonic waves from the ultrasonic transceiver to transmit the ultrasonic waves and the relay time together;
Wave measurement that measures the wave height by determining the distance between each of the sound wave repeaters and each of the ultrasonic wave transmitters / receivers based on the propagation time from transmission of the ultrasonic wave transmitted from the sound wave repeater to reception. A device,
The above wave measuring device
A distance calculator that receives the ultrasonic wave transmitted from the sonic repeater and the relay time and obtains a distance between the sonic repeater and each ultrasonic transceiver based on a propagation time from the sonic repeater; A difference calculation unit that calculates the difference between the two distance data obtained by the distance calculation unit, and a short-cycle fluctuation component that is extracted by performing high-pass filter processing on the difference between the two distance data obtained by the difference calculation unit. An expression in which each relative displacement amount on the three-dimensional coordinate axis between the two ultrasonic receivers with coefficients of the azimuth angle and the depression angle with respect to the sound wave repeater of the periodic fluctuation component extraction unit and the first ultrasonic transmitter / receiver is an unknown Is created for each sonic repeater so as to be equal to the extracted short-period fluctuation component, and at least a short-period fluctuation component is solved by solving this ternary simultaneous equation. Those constructed from short-period fluctuation component calculation section for obtaining a wave height seeking in the height direction of the displacement.

  According to the first wave measurement method and the wave measurement system, an ultrasonic wave from an ultrasonic transmitter disposed at or near the seabed is transmitted toward the sea surface, and an ocean structure and a floating body disposed on the sea surface. Receiving with the ultrasonic receiver provided below, and detecting the propagation time of the ultrasonic wave, the distance between the marine structure and the floating body and each ultrasonic transmitter is obtained, and the obtained both distances By applying high-pass filter processing to the difference in data, that is, by removing only the short-period fluctuation component that does not include the influence of seawater by removing the long-period fluctuation component, the wave height is measured. Compared to the conventional measurement method that uses ultrasonic transducers installed on the sea floor to emit ultrasonic waves toward the sea surface and reflect them on the sea surface, it is not affected by the sea surface. Even when waves are high, the wave height can be accurately measured, thus almost no falling into unmeasurable.

  According to the second wave measurement method and the wave measurement system, an ultrasonic wave is transmitted from the ultrasonic transmitter / receiver provided under the sea surface of the ocean structure and the floating body, respectively, to the sea. The ultrasonic wave from the sonic repeater placed in the vicinity is received by the ultrasonic transmitter / receiver, and the distance between the marine structure and the floating body and the sonic repeater is obtained by detecting the reciprocal propagation time of the ultrasonic wave. At the same time, by applying high-pass filter processing to the difference between the obtained distance data, that is, by removing only long-period fluctuation components that do not include the influence of seawater by removing long-period fluctuation components, Compared to the conventional measurement method, the ultrasonic wave is emitted from the ultrasonic transmitter / receiver installed on the seabed and reflected by the sea surface. Effect without receiving, i.e. even when waves are high, the wave height can be accurately measured, thus almost no falling into unmeasurable.

  According to the third wave measurement method and the wave measurement system, an ultrasonic wave is transmitted from an underwater surface of a marine structure and a floating body placed on the sea surface to the sea, and from an acoustic wave repeater placed near or near the seabed. By detecting the ultrasonic one-way propagation time by receiving each ultrasonic wave with the transmission time at each ultrasonic transmitter / receiver provided in the offshore structure and floating body. In addition, the difference between the two obtained distance data is subjected to high-pass filter processing, that is, the long-period fluctuation component is removed and only the short-period fluctuation component not including the influence of seawater is extracted. As a result, the wave height is measured (in short, it is an error-free measurement method caused by changes in the sound velocity due to changes in salinity and seawater temperature). Compared to ultrasonic waves emitted from the ultrasonic transducer installed at the bottom and reflected by the sea surface, the wave height is not affected by the sea surface, that is, even when the wave is high. Therefore, it is possible to measure the accuracy with high accuracy, so that the measurement is hardly lost.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the schematic whole structure of the wave measurement system which concerns on Example 1 of this invention. It is a perspective view which shows the coordinate system explaining the measurement principle in the same wave measurement system. It is a schematic diagram explaining the measurement principle in the same wave measurement system. It is a bird's-eye view which shows the concrete apparatus arrangement | positioning state in the sea area where the same wave measurement system is used. It is a block diagram which shows schematic structure of the wave measurement apparatus in the same wave measurement system. It is a figure which shows the schematic whole structure of the wave measurement system which concerns on Example 2 of this invention. It is a perspective view which shows the coordinate system explaining the measurement principle in the same wave measurement system. It is a schematic diagram explaining the measurement principle in the same wave measurement system. It is a block diagram which shows schematic structure of the wave measurement apparatus in the same wave measurement system. It is a figure which shows the schematic whole structure of the wave measurement system which concerns on Example 3 of this invention. It is a perspective view which shows the coordinate system explaining the measurement principle in the same wave measurement system. It is a schematic diagram explaining the measurement principle in the same wave measurement system. It is a block diagram which shows schematic structure of the wave measurement apparatus in the same wave measurement system.

Hereinafter, a wave measuring method and a wave measuring system using ultrasonic waves according to Embodiment 1 of the present invention will be described.
In the first embodiment, the description will be made assuming that the wave height is measured not only in the coastal sea area but also in a deep sea area using ultrasonic waves transmitted (launched) in water.

First, the principle of the wave measuring method according to the present invention will be schematically described.
This wave measurement method measures the amount of sea surface fluctuation (displacement), that is, wave height, by measuring the three-dimensional position of a floating body that is suspended and moored in a predetermined sea area and follows the sea surface fluctuation (displacement). Thus, this variation is measured using ultrasonic waves. Moreover, in the measurement, the first ultrasonic receiver as a reference provided in an offshore structure that hardly changes and the second ultrasonic receiver for measurement or observation provided in a floating body that changes due to waves or the like. And measuring the distance between these two ultrasonic receivers and a plurality of ultrasonic transmitters placed in the sea or at the bottom using ultrasonic waves, and the coordinate positions of both ultrasonic receivers Considering the relative displacement vector to be connected, the relative displacement vector is divided into a short-period fluctuation component having a large fluctuation and a long-period fluctuation component having a small fluctuation, and the fluctuation of the sea surface, that is, a wave is measured by obtaining the short-period fluctuation component. Is.

Hereinafter, a wave measurement system using this measurement principle will be described.
As shown in FIGS. 1 to 3, this wave measurement system is used as a reference that can be suspended and moored (arranged) on the surface of a deep sea by a mooring line (not shown) and can receive ultrasonic waves. Similarly to the marine structure 1 provided with the first ultrasonic receiver 2, for observation that can be suspended and moored at the sea surface in the deep water area and in the vicinity of the marine structure 1 and receive ultrasonic waves. The buoy 3 which is a floating body provided with the second ultrasonic receiver 4 and the buoy 3 is disposed almost directly below the buoy 3, that is, near the sea floor of the buoy 3 and the marine structure 1 to transmit ultrasonic waves toward the sea surface. At least three ultrasonic transmitters 5 to be obtained, and the ultrasonic waves transmitted by the ultrasonic transmitters 5 are received by both the ultrasonic receivers 2 and 4, and the three-dimensional position of the buoy 3, that is, the fluctuation of the buoy 3 is changed. It consists of a wave measuring device 6 that measures the wave height by detection. It is. Each of the ultrasonic receivers 2 and 4 is provided below the offshore structure 1 and the buoy 3, that is, below the sea surface (in the sea). Further, a transmitter main body for transmitting ultrasonic waves is built in the cylindrical container main body 5a of each of the ultrasonic transmitters 5 described above. FIG. 4 shows a bird's-eye view of the sea area specifically showing the arrangement of the buoy 3 and the three ultrasonic transmitters (1, 2, 3) 5.

  By the way, the marine structure 1 is a floating structure larger than the buoy 3 and is not easily affected by waves. As will be described later, this marine structure 1 is provided with an ultrasonic receiver that serves as a reference when measuring sound waves, and its position is preferably fixed (arranged in the sea with little fluctuation). It may be supported by a submerged floating body. Therefore, it is preferable to be supported by the seabed. However, if it cannot be supported by the seabed, the position of the offshore structure 1 suspended or moored on the sea surface is sometimes What is necessary is just to be able to detect every moment.

  In addition, the ultrasonic transmitter 5 can be moved by being anchored to the anchor 7 via the cable body 8 dropped on the seabed, but there is almost no ocean current in the vicinity of the seabed in the deep water area. You can consider it. That is, the position of the ultrasonic transmitter 5 may be regarded as fixed. Note that the ultrasonic transmitter 5 may be dropped and installed directly on the seabed.

  In short, the distance between the first ultrasonic receiver 2 provided in the marine structure 1 that hardly changes and the second ultrasonic receiver 4 provided in the buoy 3 that changes due to waves etc. The wave measuring device 6 based on the above measurement principle will be described below.

  This wave measuring device 6 continuously measures the distance between each of the ultrasonic receivers 2, 4 provided on the offshore structure 1 and the buoy 3 and the three ultrasonic transmitters 5 to change the buoy 3. That is, the wave height is measured by detecting the displacement of the sea surface. The wave measuring device 6 can obtain the wave height by calculation anywhere as long as there is data received from the ultrasonic wave transmitted from the ultrasonic transmitter 5. Therefore, since the wave measuring device 6 is usually arranged at the land base station K, data received by the ultrasonic receivers 2 and 4, for example, time data is transmitted to the base station K via the satellite S or the like. Then, it is obtained by the wave measuring device 6 provided in the base station K. Of course, the wave measuring device 6 is arranged on the marine structure 1 or buoy 3 side, and the wave height obtained by the wave measuring device 6 is transmitted to a predetermined location such as the base station K via the satellite S. You may do it.

  In this wave measuring method, the distance between each of the ultrasonic receivers 2 and 4 provided in the offshore structure 1 and the buoy 3 and the ultrasonic transmitter 5 disposed in the deep sea or near the seabed. Is measured using the propagation time of ultrasonic waves, and the measurement is greatly influenced by seawater. That is, since the speed of ultrasonic waves varies greatly depending on the temperature, pressure, and salinity of seawater, it is necessary to remove these fluctuation components.

  Therefore, in the first embodiment, the time variation of the fluctuation component due to the influence of these seawaters, that is, the temperature, pressure, and salinity concentration distribution of the seawater between the ultrasonic receivers 2 and 4 and the ultrasonic transmitter 5 is long. In other words, paying attention to the fact that this time change is much longer than the period of vertical movement of the buoy 3 due to waves, the influence of seawater is removed.

  Specifically, the fluctuation of the buoy 3 includes a long-period fluctuation component due to the influence of seawater and a short-period fluctuation component due to waves. Therefore, the fluctuation of the buoy 3 with respect to the reference marine structure 1 is long. By subtracting the periodic fluctuation component, the short period fluctuation component is obtained, and the height direction portion of the short period fluctuation component is obtained as the wave height.

Hereinafter, the procedure for obtaining the wave height will be described in detail.
Here, as shown in FIG. 3, the first ultrasonic receiver (0) provided in the floating structure 1 is the second ultrasonic receiver provided at a predetermined position of the reference point P ₀ and the buoy 3. (1) An explanation will be given assuming that the installation position of 2 is the observation point P ₁ and the member number assigned to the ultrasonic transmitter 5 is i (i = 1, 2, 3).

The distance ρ ₁ ⁱ between the ultrasonic transmitter i (i = 1, 2, 3) and the observation point P ₁ which is the second ultrasonic receiver is obtained by the following equation (1), and the ultrasonic transmitter i The distance ρ ₀ ⁱ to the reference point P ₀ which is the first ultrasonic receiver is obtained by the following equation (2).

ここで、上記両距離データの差（受信機間一重差とも言える）をとると、下記（３）式が得られる。

Here, when the difference between the two distance data (which can be said to be a single difference between the receivers) is taken, the following equation (3) is obtained.

ところで、超音波送信機ｉ、基準点Ｐ_０および観測点Ｐ_１は、図３に示すような位置関係にあり、ρ_０ ^ｉとρ_１ ^ｉとの距離に比べて、基準点Ｐ_０と観測点Ｐ_１との間の距離があまり大きくない場合には、上記（３）式の右辺を簡単にすることができる。

By the way, the ultrasonic transmitter i, the reference point P ₀ and the observation point P ₁ are in a positional relationship as shown in FIG. 3, and the reference point P ₀ and the observation are compared with the distance between ρ ₀ ⁱ and ρ ₁ ^i. If the distance between the point P ₁ is not so large, it is possible to simplify the right hand side of equation (3) above.

That is, the relative displacement vector between the reference point P ₀ and the observation point P ₁ is Δ * r (* indicates that the following symbol is a vector, and the same applies hereinafter), and the component of this relative displacement vector is (Δx ₍₀₁ , Δy ₀₁ , Δz ₀₁ ), the following equation (4) is obtained. Substituting this equation (4) into the above equation (3) yields the following equation (5).

なお、上記（５）式中の（ｅ_０，ｘ ^ｉ，ｅ_０，ｙ ^ｉ，ｅ_０，ｚ ^ｉ）は、基準点Ｐ_０から超音波送信機ｉに対する方向単位ベクトル（＊ｅ_０ ^ｉ）の三次元座標成分を表わしており、図３に示すように、基準点Ｐ_０から見た超音波送信機ｉの俯角θ_０ ^ｉおよび方位角ψ_０ ^ｉを用いると、下記（６）式のように表わされる。

In addition, (e _{0, x} ⁱ , e _{0, y} ⁱ , e _{0, z} ⁱ ) in the above equation (5) is a directional unit vector (* e ₀ ⁱ ) from the reference point P ₀ to the ultrasonic transmitter ⁱ . As shown in FIG. 3, using the depression angle θ ₀ ⁱ and the azimuth angle ψ ₀ ⁱ of the ultrasonic transmitter i viewed from the reference point P ₀ , as shown in FIG. It is expressed as follows.

したがって、俯角θ_０ ^ｉおよび方位角ψ_０ ^ｉを計測することにより、（ｅ_０，ｘ ^ｉ，ｅ_０，ｙ ^ｉ，ｅ_０，ｚ ^ｉ）は既知となる。なお、これらの角度θ_０ ^ｉ，ψ_０ ^ｉについては、ブイ３および超音波送信機ｉの設置時に計測することができる。

Therefore, (e _{0, x} ⁱ , e _{0, y} ⁱ , e _{0, z} ⁱ ) is known by measuring the depression angle θ ₀ ⁱ and the azimuth angle ψ ₀ ⁱ . Note that these angles θ ₀ ⁱ and ψ ₀ ⁱ can be measured when the buoy 3 and the ultrasonic transmitter i are installed.

  Then, by substituting the above equation (5) into equation (3), the following equation (7) is obtained.

なお、基準点Ｐ_０と観測点Ｐ_１との間の相対変位ベクトルΔ＊ｒ_０１を求めるのに、基準点Ｐ_０の絶対座標は不要である。

Note that the absolute coordinates of the reference point P ₀ are not required to obtain the relative displacement vector Δ * r ₀₁ between the reference point P ₀ and the observation point P ₁ .

Here, the long-period fluctuation component Δ * r1 ₀₁ (Δx1 ₀₁ , Δy1) hardly fluctuates the relative displacement vector Δ * r ₀₁ (Δx ₀₁ , Δy ₀₁ , Δz ₀₁ ) between the observation point P ₁ and the reference point P _{0. (01} , Δz1 ₀₁ ) and a short-period fluctuation component Δ * r2 ₀₁ (Δx2 ₀₁ , Δy2 ₀₁ , Δz2 ₀₁ ) having a large fluctuation, the following equation (8) is obtained.

  The number “1” following “r, x, y, z” described above represents a long-period fluctuation component, and the number “2” following “r, x, y, z” represents a short-period fluctuation component. In the following equations, the long period fluctuation component (r1, x1, y1, z1) is indicated by “hat r”, and the short period fluctuation component (r2, x2, y2, z2) is indicated by “tilde r”. Similarly for “ρ” and “φ (to be described later)”, “1” represents a long-period fluctuation component and “2” represents a short-period fluctuation component. ", The short period fluctuation component is indicated by" tilde ".

上記（８）式を（７）式に代入すると、下記（９）式が得られる。

Substituting equation (8) into equation (7) yields equation (9) below.

また、（∇ρ）_０１ ^ｉの短周期変動成分を（∇ρ２）_０１ ^ｉとすると、下記（１０）式が得られる。

When the short period fluctuation component of (∇ρ) ₀₁ ⁱ is (∇ρ2) ₀₁ ⁱ , the following equation (10) is obtained.

ここで、超音波送信器ｉと超音波受信機（０，１）との間の観測値（距離データ）をφ_０ ^ｉ，φ_１ ^ｉで表わすと、超音波送信機に起因する誤差が少ない場合には、下記（１１）式が成立する。なお、両距離データの差（∇φ）_０１ ^ｉの短周期変動成分を（∇φ２）_０１ ^ｉとする。

Here, when the observation values (distance data) between the ultrasonic transmitter i and the ultrasonic receiver (0, 1) are represented by φ ₀ ⁱ and φ ₁ ⁱ , errors caused by the ultrasonic transmitter are small. In this case, the following equation (11) is established. The short period fluctuation component of the difference (∇φ) ₀₁ ⁱ between the two distance data is assumed to be (∇φ2) ₀₁ ⁱ .

したがって、３個以上の超音波送信機により得られる距離データから３個以上の（∇φ２）_０１ ^ｉが得られれば、（１０）式より相対変位ベクトルの短周期変動成分Δ＊ｒ２_０１（Δｘ２_０１，Δｙ２_０１，Δｚ２_０１）を決定することができる。

Therefore, if three or more (∇φ2) ₀₁ ⁱ are obtained from the distance data obtained by three or more ultrasonic transmitters, the short period fluctuation component Δ * r2 ₀₁ (Δx2) of the relative displacement vector is obtained from the equation (10). ₀₁ , Δy2 ₀₁ , Δz2 ₀₁ ).

The short-period fluctuation component (∇φ2) is obtained by applying a high-pass filter process (applying a high-pass filter) to the difference (∇φ) between the raw observation data (φ ₀ , φ ₁ ).

Therefore, three ternary linear equations (10) are obtained by three ultrasonic transmitters i (i = 1, 2, 3), and these three ternary simultaneous equations are obtained. By solving, a short period fluctuation component can be obtained. Of the three x, y, and z components of the direction unit vector of the short period fluctuation component, the vertical z component corresponds to the wave height. That is, if the short-period fluctuation component (∇φ2) ₀₁ ⁱ of the difference in observation data between the reference point P ₀ and the observation point P ₁ and the ultrasonic transmitter i on the seabed is known, the wave height can be obtained. .

By the way, regarding the distance φ ⁱ between the ultrasonic receivers provided at the reference point P ₀ and the observation point P ₁ and the ultrasonic transmitter i provided on the seabed, an ultrasonic wave transmitted from the ultrasonic transmitter i is used. The propagation time until the sound wave reaches the ultrasonic receiver is t ⁱ , and the reference sound speed is a fixed value c (the actual sound speed varies greatly in the sea, but for example, the sound speed value corresponding to the temperature near the sea surface in normal years is used. If it is acceptable, the following equation (12) is obtained.

φ ⁱ = c × t ⁱ (12)
Then, the high-pass filter process is performed on the distance data φ ⁱ represented by the above equation (12) to remove the long-period fluctuation component φ 1 ^i, thereby obtaining the short-period fluctuation component φ 2 ⁱ .

  In order to detect the propagation time of the ultrasonic wave transmitted from the ultrasonic transmitter until it is received by the ultrasonic receiver, naturally, the ultrasonic wave is transmitted from the ultrasonic transmitter on the ultrasonic receiver side. The timing, i.e. the time, is determined. That is, an accurate timepiece is provided in each of the ultrasonic receiver and the ultrasonic transmitter, and the time of both is made to coincide, and the time transmitted from the ultrasonic transmitter is known in advance.

Here, the wave measuring device 6 capable of executing the above-described wave height measurement will be described with reference to FIG.
This wave measuring device 6 detects the propagation times t ₀ ⁱ and t ₁ ⁱ until the ultrasonic waves transmitted from the ultrasonic transmitter 5 are received by the first and second ultrasonic receivers 2 and 4 and buoys them. 3 and the distance calculation unit 11 that calculates the distance data φ ₀ ⁱ and φ ₁ ⁱ between the ultrasonic transmitter 5 based on the above equation (12), and the difference between the distance data obtained by the distance calculation unit (φ ₀ ⁱ −φ ₁ ⁱ ), and the difference (∇φ) ₀₁ ⁱ between the two distance data obtained by the difference calculation unit 12 is subjected to high-pass filter processing to perform long-period fluctuation components φ1 ₀ ⁱ , φ1 a short-period fluctuation component extraction unit 13 for extracting a ₁ ⁱ is removed short period fluctuation component (∇φ2) ₀₁ ^i, short-period fluctuation component obtained in this short period fluctuation component extraction unit 13 (∇φ2) ₀₁ ⁱ To create ternary linear equations for three ultrasonic transmitters 5 based on A generating unit 14, and a equation solution calculating unit 15 for solving three-way simultaneous linear equations obtained in this equation equation generating unit 14. At least the functions of the distance calculation unit 11, the difference calculation unit 12, the short cycle variation component extraction unit 13, the equation creation unit 14, the equation solution calculation unit 15, and the like are realized by a program. Of course, each component is incorporated in the same program as necessary, but here, in order to make the description easy to understand, the component is described with the component corresponding to the function.

Next, a method for measuring the wave height using the wave measuring device 6 will be described with the overall flow.
Ultrasonic waves transmitted toward the sea surface from the ultrasonic transmitter 5 on the sea floor are received by the ultrasonic receivers 2 and 4 provided on the buoy 3 floating on the sea surface. When the propagation times t ₀ ⁱ and t ₁ ⁱ with the respective ultrasonic transmitters 5 are detected, the distance calculation unit 11 detects the distance data φ ₀ ⁱ , between the ultrasonic receivers 2 and 4 and the ultrasonic transmitter 5. φ ₁ ⁱ is obtained, and both distance data φ ₀ ⁱ and φ ₁ ⁱ are input to the difference calculation unit 12 to obtain the difference (∇φ) ₀₁ ⁱ .

Next, the difference (∇φ) ₀₁ ⁱ obtained by the difference calculation unit 12 is input to the short cycle variation component extraction unit 13, where the short cycle variation component (∇φ2) ₀₁ ⁱ is extracted.
Next, the extracted short-period fluctuation component (∇φ2) ₀₁ ⁱ is input to the equation creating unit 14, and the ternary linear equations based on the above equation (5) are respectively sent to the three ultrasonic transmitters 5. Created.

Then, the created ternary linear simultaneous equations are input to the equation solution calculation unit 15, and three unknowns Δx ₀₁ , Δy ₀₁ , Δz which are displacement amounts of the relative displacement vectors between the ultrasonic receivers 2, 4. ₀₁ is obtained, and its z component is extracted as the wave height.

  As described above, according to the above-described wave measuring method and wave measuring system, the ultrasonic wave is transmitted from the ultrasonic transmitter arranged at or near the seabed toward the sea surface, and is provided below the sea surface of the marine structure and the buoy. The distances between the marine structure and the buoy and the ultrasonic transmitter are obtained by detecting the propagation time of the ultrasonic waves respectively received by the first ultrasonic receiver and the second ultrasonic receiver. By calculating the data difference and applying high-pass filtering to the difference between the two distance data, that is, by extracting only the short-period fluctuation component that does not include the influence of seawater by removing the long-period fluctuation component, Since the height is measured (in simple terms, it is an error-free measurement method caused by changes in the sound speed due to changes in salinity and seawater temperature), as in the past Compared to ultrasonic waves emitted from the ultrasonic transducer installed at the bottom and reflected by the sea surface, the wave height is not affected by the sea surface, that is, even when the wave is high. Therefore, it is possible to measure the accuracy with high accuracy, so that the measurement is hardly lost.

Hereinafter, a wave measuring method and a wave measuring system using ultrasonic waves according to the second embodiment of the present invention will be described.
In the first embodiment, the ultrasonic wave transmitted from the ultrasonic transmitter arranged on the seabed is received by the ultrasonic receivers respectively provided on the marine structure and the buoy (floating body), and the one-way propagation time of the ultrasonic wave is received. However, in the second embodiment, the ultrasonic wave transmitted from each ultrasonic transmitter / receiver provided under the sea surface of the offshore structure and the buoy is a transponder (transponder) disposed on the seabed. In other words, the round-trip propagation time of ultrasonic waves received and transmitted, that is, relayed, is detected.

The second embodiment will be described from the beginning as in the first embodiment.
First, the principle of the wave measuring method according to the present invention will be schematically described.
This wave measurement method measures the amount of sea surface fluctuation (displacement), that is, wave height, by measuring the three-dimensional position of a floating body that is suspended and moored in a predetermined sea area and follows the sea surface fluctuation (displacement). Thus, this variation is measured using ultrasonic waves. Moreover, in the measurement, the first ultrasonic transmitter / receiver as a reference provided in a marine structure that hardly changes and the second ultrasonic transmitter / receiver for measurement or observation provided in a floating body that changes due to waves or the like. And measuring each distance between the two ultrasonic transmitters / receivers and a plurality of ultrasonic repeaters arranged in the sea or at the bottom using ultrasonic waves. Considering the relative displacement vector that connects the coordinate positions in, and dividing the relative displacement vector into a short-period fluctuation component with large fluctuation and a long-period fluctuation component with small fluctuation, and obtaining this short-period fluctuation component, That is, it measures waves.

Hereinafter, a wave measurement system using this measurement principle will be described.
As shown in FIGS. 6 to 9, this wave measurement system is used as a reference that can be suspended and moored (arranged) on the surface of deep water by a mooring cable (not shown) and can transmit and receive ultrasonic waves. As with the offshore structure 21 provided with the first ultrasonic transmitter / receiver 22, the observation can be suspended and moored at the sea surface in the deep sea area and in the vicinity of the offshore structure 21 and can transmit and receive the ultrasonic waves. A buoy 23 that is a floating body provided with a second ultrasonic transmitter / receiver 24 for use and a buoy 23 that is disposed almost directly below the buoy 23, that is, near the sea floor of the buoy 23 and the marine structure 21 to direct the ultrasonic wave toward the sea surface At least three sonic repeaters 25 that can transmit and the ultrasonic waves transmitted by the sonic repeaters 25 are received by both the ultrasonic transceivers 22 and 24, and the three-dimensional position of the buoy 23, that is, the variation of the buoy 23 is detected. By detecting And a wave measuring device 26 for measuring the wave height. The ultrasonic transceivers 22 and 24 are provided below the marine structure 21 and the buoy 23, that is, below the sea surface (in the sea). The tubular container body 25a of each of the sonic repeaters 25 includes a repeater body that receives ultrasonic waves and amplifies the ultrasonic waves and transmits them to the sea surface.

  By the way, the marine structure 21 is a floating structure larger than the buoy 23 and is not easily affected by the waves. As will be described later, this marine structure 21 is provided with a reference ultrasonic transceiver when measuring sound waves, and its position is preferably fixed (arranged in the sea with little fluctuation). It may be supported by a submerged floating body). Therefore, it is preferable to be supported by the seabed. However, if it cannot be supported by the seabed, the position of the offshore structure 21 suspended or moored on the sea surface is sometimes What is necessary is just to be able to detect every moment.

  Further, the sonic repeater 25 can be moved by being moored, for example, by a ridge 27 dropped on the seabed via a cable body 28. However, since there is almost no current near the seabed in the deep water, it is regarded as a stationary state. There is no problem. That is, the position of the sound wave repeater 25 may be regarded as fixed. Note that the sonic repeater 25 may be dropped and installed directly on the seabed.

  In short, the distance between the first ultrasonic transmitter / receiver 22 provided in the marine structure 21 that hardly changes and the second ultrasonic transmitter / receiver 24 provided in the buoy 23 that changes due to waves or the like is set to The wave measuring device 26 based on the above measurement principle will be described below.

  The wave measuring device 26 continuously measures the distance between each of the ultrasonic transmitters / receivers 22 and 24 provided on the offshore structure 21 and the buoy 23 and the three sonic repeaters 25 to thereby change the buoy 23. It detects, that is, detects the sea level displacement and measures the wave height. The wave measuring device 26 can obtain the wave height by calculation anywhere if there is ultrasonic reception data from the sound wave repeater 25. Therefore, since the wave measuring device 26 is normally arranged at the land base station K, data received by the ultrasonic transceivers 22 and 24, for example, time data is transmitted to the base station K via the satellite S or the like. Then, it is obtained by the wave measuring device 26 provided in the base station K. Of course, the wave measuring device 26 is arranged on the offshore structure 21 or buoy 23 side, and the wave height obtained by the wave measuring device 26 is transmitted to a predetermined place such as the base station K via the satellite S. You may do it.

  And in this wave measuring method, the distance between each ultrasonic transmitter-receiver 22, 24 provided in the marine structure 21 and the buoy 23 and the sonic repeater 25 disposed in the deep sea or near the seabed is obtained. Measurement is performed using the propagation time of ultrasonic waves, but the measurement is greatly influenced by seawater. That is, since the speed of ultrasonic waves varies greatly depending on the temperature, pressure, and salinity of seawater, it is necessary to remove these fluctuation components.

  Therefore, in the second embodiment, the variation due to the influence of the seawater, that is, the time change of the temperature, pressure, and salinity concentration distribution of the seawater between the ultrasonic transceivers 22 and 24 and the sonic repeater 25 is long. In other words, paying attention to the fact that this time change is much longer than the period of vertical movement of the buoy 23 caused by waves, the influence of seawater is removed.

  Specifically, the fluctuation of the buoy 23 includes a long-period fluctuation component due to the influence of seawater and a short-period fluctuation component due to waves, and accordingly, the fluctuation data of the buoy 23 relative to the reference offshore structure 21 is long. By subtracting the periodic fluctuation component, the short period fluctuation component is obtained, and the height direction portion of the short period fluctuation component is obtained as the wave height.

Hereinafter, the procedure for obtaining the wave height will be described in detail.
Here, as shown in FIG. 8, the first ultrasonic transmitter / receiver (0) provided in the floating structure 21 is the second ultrasonic transmitter / receiver provided at a predetermined position of the reference point P ₀ and the buoy 23. The description will be made assuming that the installation position of (1) is the observation point P ₁ and the member number assigned to the sound wave repeater 25 is i (i = 1, 2, 3).

The distance ρ ₁ ⁱ between the sonic repeater i (i = 1, 2, 3) and the observation point P ₁ which is the second ultrasonic transceiver is obtained by the following equation (21). The distance ρ ₀ ⁱ to the reference point P ₀ which is an ultrasonic transceiver is obtained by the following equation (22).

ここで、上記両距離の差（送受信機間一重差に相当する）をとると、下記（２
３）式が得られる。

Here, when the difference between the two distances (corresponding to a single difference between the transmitter and the receiver) is taken, the following (2
3) Equation is obtained.

ところで、音波中継器ｉ、基準点Ｐ_０および観測点Ｐ_１は、図８に示すような位置関係にあり、ρ_０ ^ｉとρ_１ ^ｉとの距離に比べて、基準点Ｐ_０と観測点Ｐ_１との間の距離があまり大きくない場合には、上記（２３）式の右辺を簡単にすることができる。

By the way, the sound wave repeater i, the reference point P ₀ and the observation point P ₁ are in a positional relationship as shown in FIG. 8, and the reference point P ₀ and the observation point are compared with the distance between ρ ₀ ⁱ and ρ ₁ ^i. If the distance between the P ₁ is not so large, it is possible to simplify the right side of the above equation (23).

That is, the relative displacement vector between the reference point P ₀ and the observation point P ₁ is Δ * r (* indicates that the following symbol is a vector, and the same applies hereinafter), and the component of this relative displacement vector is (Δx ₍₀₁ , Δy ₀₁ , Δz ₀₁ ), the following equation (24) is obtained. Substituting equation (24) into equation (23) gives equation (25) below.

なお、上記（２５）式中の（ｅ_０，ｘ ^ｉ，ｅ_０，ｙ ^ｉ，ｅ_０，ｚ ^ｉ）は、基準点Ｐ_０から音波中継器ｉに対する方向単位ベクトル（＊ｅ_０ ^ｉ）の三次元座標成分を表わしており、図７に示すように、基準点Ｐ_０から見た音波中継器ｉの俯角θ_０ ^ｉおよび方位角ψ_０ ^ｉを用いると、下記（２６）式のように表わされる。

Note that (e _{0, x} ⁱ , e _{0, y} ⁱ , e _{0, z} ⁱ ) in the above equation (25) is the direction unit vector (* e ₀ ⁱ ) from the reference point P ₀ to the sound wave repeater ⁱ . As shown in FIG. 7, when the depression angle θ ₀ ⁱ and the azimuth angle ψ ₀ ⁱ of the sound wave repeater i viewed from the reference point P ₀ are used, as shown in FIG. Represented.

したがって、俯角θ^ｉおよび方位角ψ^ｉを計測することにより、（ｅ_０，ｘ ^ｉ，ｅ_０，ｙ ^ｉ，ｅ_０，ｚ ^ｉ）は既知となる。なお、これらの角度θ_０ ^ｉ，ψ_０ ^ｉについては、ブイ２３および音波中継器ｉの設置時に計測することができる。

Therefore, by measuring the depression angle θ ⁱ and the azimuth angle ψ ⁱ , (e _{0, x} ⁱ , e _{0, y} ⁱ , e _{0, z} ⁱ ) becomes known. These angles θ ₀ ⁱ and ψ ₀ ⁱ can be measured when the buoy 23 and the sonic repeater i are installed.

  Then, by substituting the above equation (25) into equation (23), the following equation (27) is obtained.

なお、基準点Ｐ_０と観測点Ｐ_１との間の相対変位ベクトルΔ＊ｒ_０１を求めるのに、基準点Ｐ_０の絶対座標は不要である。

Note that the absolute coordinates of the reference point P ₀ are not required to obtain the relative displacement vector Δ * r ₀₁ between the reference point P ₀ and the observation point P ₁ .

Here, the long-period fluctuation component Δ * r1 ₀₁ (Δx1 ₀₁ , Δy1) that hardly changes the relative displacement vector Δ * r ₀₁ (Δx ₀₁ , Δy ₀₁ , Δz ₀₁ ) between the reference point P ₀ and the observation point P _{1. (01} , Δz1 ₀₁ ) and short-period fluctuation component Δ * r2 ₀₁ (Δx2 ₀₁ , Δy2 ₀₁ , Δz2 ₀₁ ) having a large fluctuation, the following equation (28) is obtained.

  The number “1” following “r, x, y, z” described above represents a long-period fluctuation component, and the number “2” following “r, x, y, z” represents a short-period fluctuation component. Also, in the following equations, the long period fluctuation component (r1, x1, y1, z1) is “hat r”, and the short period fluctuation component (r2, x2, y2, z2) is “tilde r”. Show. Similarly, for “ρ” and “φ (to be described later)”, “1” represents a long-period fluctuation component, “2” represents a short-period fluctuation component, and the long-period fluctuation component is “ The “hat” and the short period fluctuation component are indicated by “tilde”.

上記（２８）式を（２７）式に代入すると、下記（２９）式が得られる。

By substituting the above equation (28) into equation (27), the following equation (29) is obtained.

また、（∇ρ）_０１ ^ｉの短周期変動成分を（∇ρ２）_０１ ^ｉとすると、下記（３０）式が得られる。

Further, when the short period fluctuation component of (∇ρ) ₀₁ ⁱ is (∇ρ2) ₀₁ ⁱ , the following equation (30) is obtained.

ここで、音波中継器ｉと超音波送受信機（０，１）との間の観測値（距離データ）をφ_０ ^ｉ，φ_１ ^ｉで表わすと、音波中継器に起因する誤差が少ない場合には、下記（３１）式が成立する。なお、両距離データの差（∇φ）_０１ ^ｉの短周期変動成分を（∇φ２）_０１ ^ｉとする。

Here, when the observation values (distance data) between the sonic repeater i and the ultrasonic transmitter / receiver (0, 1) are expressed as φ ₀ ⁱ and φ ₁ ⁱ , the error due to the sonic repeater is small. The following equation (31) is established. The short period fluctuation component of the difference (∇φ) ₀₁ ⁱ between the two distance data is assumed to be (∇φ2) ₀₁ ⁱ .

したがって、３個以上の音波中継器により得られる距離データから３個以上の（∇φ２）_０１ ^ｉが得られれば、（３０）式より相対変位ベクトルの短周期変動成分Δ＊ｒ２_０１（Δｘ２_０１，Δｙ２_０１，Δｚ２_０１）を決定することができる。

Therefore, if three or more (∇φ2) ₀₁ ⁱ are obtained from the distance data obtained by three or more acoustic wave repeaters, the short period fluctuation component Δ * r2 ₀₁ (Δx2 _{01 of the} relative displacement vector is obtained from the equation (30). , Δy2 ₀₁ , Δz2 ₀₁ ).

The short-period fluctuation component (∇φ2) is obtained by applying a high-pass filter process (applying a high-pass filter) to the difference (∇φ) between the raw observation data (φ ₀ , φ ₁ ).

Accordingly, three ternary linear equations (30) (i = 1, 2, 3) are obtained by the three sound wave repeaters i, and these three ternary linear simultaneous equations are solved. Thus, the short cycle fluctuation component can be obtained. Of the three x, y, and z components of the direction unit vector of the short period fluctuation component, the vertical z component corresponds to the wave height. That is, if the short-period fluctuation component (∇φ2) ₀₁ ⁱ of the difference in observation data between the reference point P ₀ and the observation point P ₁ and the ultrasonic transmitter i on the seabed is known, the wave height can be obtained. .

By the way, regarding the distance ρ ⁱ between the ultrasonic transmitter / receiver provided at the reference point P ₀ and the observation point P ₁ and the ultrasonic repeater i provided on the seabed, the ultrasonic wave transmitted from the ultrasonic transmitter / receiver is transmitted. The round-trip propagation time to reach the ultrasonic transmitter / receiver again via the sonic repeater i is t ⁱ , and the reference sound speed is a fixed value c (the actual sound speed changes greatly in the sea, If the corresponding sound velocity value can be used), the following equation (32) is obtained.

φ ⁱ = c × t ⁱ / 2 (32)
Then, by removing the (32) long-period fluctuation component .phi.1 ⁱ by performing high-pass filtering the distance data phi ⁱ of the formula, short-period fluctuation component .phi.2 ⁱ is determined.

Here, the wave measuring device 26 capable of executing the above-described wave height measurement will be described with reference to FIG.
The wave measuring device 26 uses the first and second ultrasonic transceivers 22 and 24 to transmit the ultrasonic waves transmitted (emitted) from the first and second ultrasonic transceivers 22 and 24 via the sonic repeater 25. A distance calculation unit 31 that detects the round-trip propagation times t ₀ ⁱ and t ₁ ⁱ until reception and calculates the distances φ ₀ ⁱ and φ ₁ ⁱ between the buoy 23 and the sound wave repeater 25 based on the above equation (32); The difference calculation unit 32 for obtaining the difference (φ ₀ ⁱ −φ ₁ ⁱ ) between the two distance data obtained by the distance calculation unit 31 and the difference (∇φ) between the two distance data obtained by the difference calculation unit 32 to _{01 i} by performing high-pass filtering the long period fluctuation component (∇φ1) to ₀₁ ⁱ to remove short-period fluctuation component (∇φ2) ₀₁ ⁱ and short-period fluctuation component extraction unit 33 for extracting, this short-period fluctuation component short period fluctuation component obtained by the extraction section 33 _{(∇φ2) 01} based on An equation creating unit 34 that creates a ternary linear equation for the three sonic repeaters 25 and an equation solution calculating unit 35 that solves the ternary simultaneous equations obtained by the equation formula creating unit 34. ing. At least the functions of the distance calculation unit 31, the difference calculation unit 32, the short cycle variation component extraction unit 33, the equation creation unit 34, the equation solution calculation unit 35, and the like are realized by a program. Of course, each component is incorporated in the same program as necessary, but here, in order to make the description easy to understand, the component is described with the component corresponding to the function.

Next, a method for measuring the wave height using the wave measuring device 26 will be described with the overall flow.
The ultrasonic waves transmitted from the first and second ultrasonic transmitters / receivers 22, 24 provided in the offshore structure 21 and the buoy 23 toward the sonic repeater 25 on the sea floor are relayed by the sonic repeater 25. When received by the ultrasonic transmission / reception units 22 and 24 and their round-trip propagation times t ₀ ⁱ and t ₁ ⁱ are detected, the distance calculation unit 31 receives the ultrasonic transmission / reception units 22 and 24 and the ultrasonic relay unit 25. Distance data φ ₀ ⁱ and φ ₁ ⁱ are respectively obtained, and both distance data φ ₀ ⁱ and φ ₁ ⁱ are input to the difference calculation unit 32 to obtain the difference (∇φ) ₀₁ ⁱ .

Next, the difference (∇φ) ₀₁ ⁱ obtained by the difference calculation unit 32 is input to the short cycle variation component extraction unit 33, where the short cycle variation component (∇φ2) ₀₁ ⁱ is extracted.
Next, the extracted short-period fluctuation component (∇φ2) ₀₁ ⁱ is input to the equation creating unit 34, and ternary linear equations based on the above equation (25) are created for the three sound wave repeaters 25, respectively. Is done.

Then, the created ternary linear simultaneous equations are input to the equation solution calculation unit 35, and three unknowns Δx ₀₁ , Δy ₀₁ , Δz which are displacement amounts of relative displacement vectors between the ultrasonic receivers 22, 24. ₀₁ is obtained, and its z component is extracted as the wave height.

  As described above, according to the wave measuring method and the wave measuring system, the sound waves disposed near or on the seabed from the first ultrasonic transmitter / receiver and the second ultrasonic transmitter / receiver provided below the surface of the marine structure and buoy. By transmitting ultrasonic waves toward the repeater, receiving the ultrasonic waves relayed by the ultrasonic repeaters with the two ultrasonic transmitters and receivers, and detecting the round-trip propagation time of the ultrasonic waves, The distance between the buoy and the sonic repeater is determined, the difference between the two distance data is determined, and a high-pass filter is applied to the difference between the two distance data. The wave height is measured by extracting only the short-period fluctuation components that are not included (in short, sound velocity changes due to changes in salinity and seawater temperature are brought about. This is an error-free measurement method). Compared to the conventional measurement method, the ultrasonic wave is emitted from the ultrasonic transducer installed on the seabed and reflected by the sea surface. Even when the waves are not received, that is, when the waves are high, the wave height can be measured with high accuracy, and therefore the measurement is hardly lost.

Hereinafter, a wave measuring method and a wave measuring system using ultrasonic waves according to the third embodiment of the present invention will be described.
In the second embodiment, the ultrasonic wave transmitted from the ultrasonic transmitter / receiver provided under the sea surface of the buoy (floating body) is received and transmitted by the sonic repeater (also referred to as a transponder) disposed near the sea floor. In other words, the round-trip propagation time of the relayed ultrasonic wave is detected, but in the third embodiment, the one-way propagation time of the ultrasonic wave relayed by the sound wave repeater is detected.

In the third embodiment, as in the second embodiment, it will be described from the beginning.
First, the principle of the wave measuring method according to the present invention will be schematically described.
This wave measurement method measures the amount of sea surface fluctuation (displacement), that is, wave height, by measuring the three-dimensional position of a floating body that is suspended and moored in a predetermined sea area and follows the sea surface fluctuation (displacement). Thus, this variation is measured using ultrasonic waves. Moreover, in the measurement, the first ultrasonic transmitter / receiver as a reference provided in a marine structure that hardly changes and the second ultrasonic transmitter / receiver for measurement or observation provided in a floating body that changes due to waves or the like. And measuring each distance between the two ultrasonic transmitters / receivers and a plurality of ultrasonic repeaters arranged in the sea or at the bottom using ultrasonic waves. Considering the relative displacement vector that connects the coordinate positions in, and dividing the relative displacement vector into a short-period fluctuation component with large fluctuation and a long-period fluctuation component with small fluctuation, and obtaining this short-period fluctuation component, That is, it measures waves.

Hereinafter, a wave measurement system using this measurement principle will be described.
As shown in FIGS. 10 to 13, this wave measurement system is used as a reference that can be suspended and moored (arranged) on a deep sea surface by a mooring cable (not shown) and can transmit and receive ultrasonic waves. As with the offshore structure 41 provided with the first ultrasonic transmitter / receiver 42, the observation can be suspended and moored at the sea surface in the deep sea area and in the vicinity of the offshore structure 1 and can transmit and receive ultrasonic waves. A buoy 43 which is a floating body provided with a second ultrasonic transmitter / receiver 44 for use, and is arranged almost directly below the buoy 43, that is, near the sea floor of the buoy 43 and the marine structure 21 to direct the ultrasonic wave toward the sea surface. At least three sound wave repeaters 45 that can be transmitted, and the ultrasonic waves transmitted by the sound wave repeater 45 are received by both the ultrasonic transmitters and receivers 42 and 44, and the three-dimensional position of the buoy 43, that is, the fluctuation of the buoy 43 is measured. To detect Ri and a wave measuring device 46 for measuring the wave height. In addition, each said ultrasonic transmitter / receiver 42,44 is provided under the marine structure 41 and the buoy 43, ie, under the sea surface (underwater). The tubular container body 45a of each of the sonic repeaters 45 contains a repeater body that receives ultrasonic waves and amplifies the ultrasonic waves and transmits them to the sea surface.

  The sonic repeater 45 is provided with a highly accurate clock, and when transmitting and receiving an ultrasonic wave, a signal of the transmission time (which is a time stamp and can also be said as a relay time) is also transmitted. From the transmission and reception of the ultrasonic wave, a clock synchronized with the clock provided in the sonic repeater 45 (at the same time) is also provided on the ultrasonic transceivers 42 and 44 side. One-way propagation time can be detected.

  By the way, the offshore structure 41 is a floating structure larger than the buoy 43 and is not easily affected by waves. As will be described later, this marine structure 41 is provided with a reference ultrasonic transceiver when measuring sound waves, and its position is preferably fixed (arranged in the sea with little fluctuation). It may be supported by a submerged floating body). Therefore, it is preferable that it is supported by the seabed, but if it cannot be supported by the seabed, the position of the offshore structure 41 suspended or moored on the sea surface is sometimes What is necessary is just to be able to detect every moment.

  In addition, the sonic repeater 45 can be moved by being anchored to the anchor 47, for example, via the cable body 48, which is dropped on the seabed. There is no problem. That is, the position of the sound wave repeater 45 may be regarded as fixed. The sonic repeater 45 may be dropped and installed directly on the seabed.

  Briefly speaking, the distance between the first ultrasonic transmitter / receiver 42 provided in the offshore structure 41 that hardly changes and the second ultrasonic transmitter / receiver 44 provided in the buoy 43 that is changed due to waves or the like is set to A wave measuring device 46 based on the above measurement principle will be described below.

  The wave measuring device 46 continuously measures the distance between each of the ultrasonic transmitters / receivers 42 and 44 provided in the offshore structure 41 and the buoy 43 and the three sonic repeaters 45 to thereby change the buoy 43. It detects, that is, detects the sea level displacement and measures the wave height. The wave measuring device 46 can obtain the wave height by calculation anywhere if there is ultrasonic reception data from the sonic repeater 45. Therefore, since the wave measuring device 46 is normally arranged at the land base station K, data received by the ultrasonic transceivers 42 and 44, for example, time data is transmitted to the base station K via the satellite S or the like. Then, it is obtained by the wave measuring device 46 provided in the base station K. Of course, the wave measuring device 46 is disposed on the offshore structure 41 or buoy 43 side, and the wave height obtained by the wave measuring device 46 is transmitted to a predetermined location such as the base station K via the satellite S. You may do it.

  In this wave measuring method, the distance between each of the ultrasonic transceivers 42 and 44 provided in the offshore structure 41 and the buoy 43 and the sonic repeater 45 disposed in the deep sea or near the seabed is obtained. Measurement is performed using the propagation time of ultrasonic waves, but the measurement is greatly influenced by seawater. That is, since the speed of ultrasonic waves varies greatly depending on the temperature, pressure, and salinity of seawater, it is necessary to remove these fluctuation components.

  Therefore, in the third embodiment, the variation due to the influence of the seawater, that is, the time change of the temperature, pressure and salinity concentration distribution of the seawater between the ultrasonic transceivers 42 and 44 and the sonic repeater 45 is long. In other words, paying attention to the fact that this time change is much longer than the period of vertical movement of the buoy 43 caused by waves, the influence of seawater is removed.

  Specifically, the fluctuation of the buoy 43 includes a long-period fluctuation component due to the influence of seawater and a short-period fluctuation component due to waves. Therefore, the fluctuation data of the buoy 43 with respect to the reference offshore structure 41 is long. By subtracting the periodic fluctuation component, the short period fluctuation component is obtained, and the height direction portion of the short period fluctuation component is obtained as the wave height.

Hereinafter, the procedure for obtaining the wave height will be described in detail.
Here, as shown in FIG. 12, the first ultrasonic transmitter / receiver (0) provided in the floating structure 41 is used as the second ultrasonic transmitter / receiver provided at a predetermined position of the reference point P ₀ and the buoy 43. The description will be made assuming that the installation position of (1) is the observation point P ₁ and the member number assigned to the sound wave repeater 45 is i (i = 1, 2, 3).

The distance ρ ₁ ⁱ between the sonic repeater i (i = 1, 2, 3) and the observation point P ₁ which is the second ultrasonic transceiver is obtained by the following equation (41). The distance ρ ₀ ⁱ to the reference point P ₀ that is an ultrasonic transceiver is obtained by the following equation (42).

ここで、上記両距離の差（送受信機間一重差に相当する）をとると、下記（４
３）式が得られる。

Here, when the difference between the two distances (corresponding to a single difference between the transmitter and the receiver) is taken, the following (4
3) Equation is obtained.

ところで、音波中継器ｉ、基準点Ｐ_０および観測点Ｐ_１は、図１２に示すような位置関係にあり、ρ_０ ^ｉとρ_１ ^ｉとの距離に比べて、基準点Ｐ_０と観測点Ｐ_１との間の距離があまり大きくない場合には、上記（４３）式の右辺を簡単にすることができる。

By the way, the sound wave repeater i, the reference point P ₀ and the observation point P ₁ are in a positional relationship as shown in FIG. 12, and the reference point P ₀ and the observation point are compared with the distance between ρ ₀ ⁱ and ρ ₁ ^i. If the distance between the P ₁ is not so large, it is possible to simplify the right side of the above expression (43).

That is, the relative displacement vector between the reference point P ₀ and the observation point P ₁ is Δ * r (* indicates that the following symbol is a vector, and the same applies hereinafter), and the component of this relative displacement vector is (Δx ₍₀₁ , Δy ₀₁ , Δz ₀₁ ), the following equation (44) is obtained. Substituting equation (44) into equation (43) gives equation (45) below.

なお、上記（４５）式中の（ｅ_０，ｘ ^ｉ，ｅ_０，ｙ ^ｉ，ｅ_０，ｚ ^ｉ）は、基準点Ｐ_０から音波中継器ｉに対する方向単位ベクトル（＊ｅ_０ ^ｉ）の三次元座標成分を表わしており、図１１に示すように、基準点Ｐ_０から見た音波中継器ｉの俯角θ_０ ^ｉおよび方位角ψ_０ ^ｉを用いると、下記（４６）式のように表わされる。

Note that (e _{0, x} ⁱ , e _{0, y} ⁱ , e _{0, z} ⁱ ) in the above equation (45) is the direction unit vector (* e ₀ ⁱ ) from the reference point P ₀ to the sound wave repeater ⁱ . As shown in FIG. 11, when the depression angle θ ₀ ⁱ and the azimuth angle ψ ₀ ⁱ of the sound wave repeater i viewed from the reference point P ₀ are used, as shown in FIG. Represented.

したがって、俯角θ^ｉおよび方位角ψ^ｉを計測することにより、（ｅ_０，ｘ ^ｉ，ｅ_０，ｙ ^ｉ，ｅ_０，ｚ ^ｉ）は既知となる。なお、これらの角度θ_０ ^ｉ，ψ_０ ^ｉについては、ブイ４３および音波中継器ｉの設置時に計測することができる。

Therefore, by measuring the depression angle θ ⁱ and the azimuth angle ψ ⁱ , (e _{0, x} ⁱ , e _{0, y} ⁱ , e _{0, z} ⁱ ) becomes known. Note that these angles θ ₀ ⁱ and ψ ₀ ⁱ can be measured when the buoy 43 and the sonic repeater i are installed.

  Then, by substituting the above equation (45) into equation (43), the following equation (47) is obtained.

なお、基準点Ｐ_０と観測点Ｐ_１との間の相対変位ベクトルΔ＊ｒ_０１を求めるのに、基準点Ｐ_０の絶対座標は不要である。

Note that the absolute coordinates of the reference point P ₀ are not required to obtain the relative displacement vector Δ * r ₀₁ between the reference point P ₀ and the observation point P ₁ .

Here, the long-period fluctuation component Δ * r1 ₀₁ (Δx1 ₀₁ , Δy1) that hardly changes the relative displacement vector Δ * r ₀₁ (Δx ₀₁ , Δy ₀₁ , Δz ₀₁ ) between the reference point P ₀ and the observation point P _{1. (01} , Δz1 ₀₁ ) and a short-period fluctuation component Δ * r2 ₀₁ (Δx2 ₀₁ , Δy2 ₀₁ , Δz2 ₀₁ ) having a large fluctuation, the following equation (48) is obtained.

  The number “1” following “r, x, y, z” described above represents a long-period fluctuation component, and the number “2” following “r, x, y, z” represents a short-period fluctuation component. Also, in the following equations, the long period fluctuation component (r1, x1, y1, z1) is “hat r”, and the short period fluctuation component (r2, x2, y2, z2) is “tilde r”. Show. Similarly, for “ρ” and “φ (to be described later)”, “1” represents a long-period fluctuation component, “2” represents a short-period fluctuation component, and the long-period fluctuation component is “ The “hat” and the short period fluctuation component are indicated by “tilde”.

上記（４８）式を（４７）式に代入すると、下記（４９）式が得られる。

Substituting the above equation (48) into equation (47) yields the following equation (49).

また、（∇ρ）_０１ ^ｉの短周期変動成分を（∇ρ２）_０１ ^ｉとすると、下記（５０）式が得られる。

When the short period fluctuation component of (∇ρ) ₀₁ ⁱ is (∇ρ2) ₀₁ ⁱ , the following equation (50) is obtained.

ここで、音波中継器ｉと超音波送受信機（０，１）との間の観測値（距離データ）をφ_０ ^ｉ，φ_１ ^ｉで表わすと、音波中継器に起因する誤差が少ない場合には、下記（５１）式が成立する。なお、両距離データの差（∇φ）_０１ ^ｉの短周期変動成分を（∇φ２）_０１ ^ｉとする。

Here, when the observation values (distance data) between the sonic repeater i and the ultrasonic transmitter / receiver (0, 1) are expressed as φ ₀ ⁱ and φ ₁ ⁱ , the error due to the sonic repeater is small. The following equation (51) is established. The short period fluctuation component of the difference (∇φ) ₀₁ ⁱ between the two distance data is assumed to be (∇φ2) ₀₁ ⁱ .

したがって、３個以上の音波中継器により得られる距離データから３個以上の（∇φ２）_０１ ^ｉが得られれば、（５０）式より相対変位ベクトルの短周期変動成分Δ＊ｒ２_０１（Δｘ２_０１，Δｙ２_０１，Δｚ２_０１）を決定することができる。

Therefore, if three or more (∇φ2) ₀₁ ⁱ are obtained from the distance data obtained by three or more acoustic wave repeaters, the short period fluctuation component Δ * r2 ₀₁ (Δx2 _{01 of the} relative displacement vector is obtained from the equation (50). , Δy2 ₀₁ , Δz2 ₀₁ ).

The short-period fluctuation component (∇φ2) is obtained by applying a high-pass filter process (applying a high-pass filter) to the difference (∇φ) between the raw observation data (φ ₀ , φ ₁ ).

Therefore, three ternary linear equations (50) are obtained by three sonic repeaters i (i = 1, 2, 3), and these three ternary linear simultaneous equations are solved. Thus, the short cycle fluctuation component can be obtained. Of the three x, y, and z components of the direction unit vector of the short period fluctuation component, the vertical z component corresponds to the wave height. That is, if the short-period fluctuation component (∇φ2) ₀₁ ⁱ of the difference in observation data between the reference point P ₀ and the observation point P ₁ and the ultrasonic transmitter i on the seabed is known, the wave height can be obtained. .

By the way, regarding the distance ρ ⁱ between the ultrasonic transmitter / receiver provided at the reference point P ₀ and the observation point P ₁ and the ultrasonic repeater i provided on the seabed, the ultrasonic wave transmitted from the ultrasonic repeater i is not transmitted. The one-way propagation time to reach the ultrasonic transmitter / receiver is t ⁱ , and the reference sound speed is a fixed value c (the actual sound speed varies greatly in the sea, but for example, the sound speed value corresponding to the temperature near the sea surface in normal years may be used. If it is acceptable, it is obtained by the following equation (52).

φ ⁱ = c × t ⁱ (52)
Then, the high-pass filter process is performed on the distance data φ ⁱ represented by the above equation (52) to remove the long-period fluctuation component φ1 ^i, thereby obtaining the short-period fluctuation component φ2 ⁱ .

Here, a wave measuring device 46 capable of executing the above-described wave height measurement will be described with reference to FIG.
The wave measuring device 46 uses the first and second ultrasonic transceivers 42 and 44 to transmit the ultrasonic waves transmitted (emitted) from the first and second ultrasonic transceivers 42 and 44 via the acoustic repeater 45. A distance calculation unit 51 that detects one-way propagation times t ₀ ⁱ and t ₁ ⁱ until reception and calculates the distances φ ₀ ⁱ and φ ₁ ⁱ between the buoy 43 and the sound wave repeater 45 based on the above equation (52); The difference calculation unit 52 for obtaining the difference (φ ₀ ⁱ −φ ₁ ⁱ ) between the two distance data obtained by the distance calculation unit 51 and the difference (∇φ) between the two distance data obtained by the difference calculation unit 52 to _{01 i} by performing high-pass filtering the long period fluctuation component (∇φ1) to ₀₁ ⁱ to remove short-period fluctuation component (∇φ2) ₀₁ ⁱ and short-period fluctuation component extraction section 53 for extracting, this short-period fluctuation component In the short period fluctuation component (∇φ2) ₀₁ ⁱ obtained by the extraction unit 53 An equation creating unit 54 that creates ternary linear equations for the three sound wave repeaters 45 and an equation solution computing unit 55 that solves the ternary simultaneous equations obtained by the equation formula creating unit 54. ing. At least the functions of the distance calculation unit 51, the difference calculation unit 52, the short cycle variation component extraction unit 53, the equation creation unit 54, the equation solution calculation unit 55, and the like are realized by a program. Of course, each component is incorporated in the same program as necessary, but here, in order to make the description easy to understand, the component is described with the component corresponding to the function.

Next, a method for measuring the wave height using the wave measuring device 46 will be described with the overall flow.
The ultrasonic waves transmitted from the first and second ultrasonic transceivers 42 and 44 provided in the offshore structure 41 and the buoy 43 toward the sonic repeater 45 on the sea floor are received by the sonic repeater 45, Simultaneously with this reception, the ultrasonic wave and the signal of the transmission time are transmitted toward the sea surface.

The ultrasonic waves are received by the ultrasonic transmission / reception units 42 and 44, and when the one-way propagation times t ₀ ⁱ and t ₁ ⁱ are detected, the distance calculation unit 51 and the ultrasonic transmission / reception units 42 and 44 and the sound waves. The distance data φ ₀ ⁱ and φ ₁ ⁱ with the repeater 45 are respectively obtained, and both the distance data φ ₀ ⁱ and φ ₁ ⁱ are input to the difference calculation unit 52 and the difference (∇φ) ₀₁ ⁱ is obtained. Desired.

Next, the difference (∇φ) ₀₁ ⁱ obtained by the difference calculation unit 52 is input to the short cycle variation component extraction unit 53, where the short cycle variation component (∇φ2) ₀₁ ⁱ is extracted.
Next, the extracted short period fluctuation component (∇φ2) ₀₁ ⁱ is input to the equation creation unit 54, and three-way linear equations based on the above equation (45) are created for the three sound wave repeaters 45, respectively. Is done.

Then, the created ternary linear simultaneous equations are input to the equation solution calculation unit 55, and three unknowns Δx ₀₁ , Δy ₀₁ , Δz which are displacement amounts of the relative displacement vectors between the ultrasonic receivers 42, 44 are input. ₀₁ is obtained, and its z component is extracted as the wave height.

  As described above, according to the above-described wave measuring method and wave measuring system, an ocean wave structure disposed on the sea surface and a sound wave repeater disposed on the sea floor or in the vicinity of the sea floor by transmitting ultrasonic waves from below the sea surface to the sea. By receiving ultrasonic waves from the satellite together with the transmission time at each ultrasonic transmitter / receiver provided on the ocean structure and floating body, and detecting the one-way propagation time of the ultrasound, the ocean structure and the floating body and acoustic wave repeater And the high-pass filter is applied to the difference between the obtained distance data, that is, the long-period fluctuation component is removed and only the short-period fluctuation component that does not include the influence of seawater is extracted. As a result, the wave height is measured (in short, it is an error-free measurement method caused by changes in the sound speed due to changes in salinity and seawater temperature). Compared to ultrasonic waves transmitted from the ultrasonic transducer installed on the seabed toward the sea surface and reflected and measured at the sea surface, the wave height is not affected by the sea surface, that is, even when the wave is high. Therefore, it is possible to measure the accuracy with high accuracy, so that the measurement is hardly lost.

1 marine structure 2 first ultrasonic receiver 3 buoy (floating body)
4 Second Ultrasonic Receiver 5 Ultrasonic Transmitter 6 Wave Measuring Device 11 Distance Calculation Unit 12 Difference Calculation Unit 13 Short Period Variation Component Extraction Unit 14 Equation Creation Unit 15 Equation Solution Calculation Unit 21 Marine Structure 22 First Ultrasonic Transmission / Reception Machine 23 buoy (floating body)
24 Second ultrasonic transmitter / receiver 25 Sound wave repeater 26 Wave measuring device 31 Distance calculator 32 Difference calculator 33 Short-period fluctuation component extractor 34 Equation generator 35 Equation solution calculator 41 Marine structure 42 First ultrasonic transmitter / receiver 43 Buoy
44 Second ultrasonic transmitter / receiver 45 Sound wave repeater 46 Wave measuring device 51 Distance calculation unit 52 Difference calculation unit 53 Short period variation component extraction unit 54 Equation creation unit 55 Equation solution calculation unit

Claims (6)

A wave measurement method for measuring the height of a wave in a predetermined sea area by detecting a change in a floating body suspended or moored on the sea surface,
At least three marine structures and seabed or ocean floor near below the floating bodies are not be affected by waves than the floating body is larger than the floating while being suspended, anchored to the sea surface in a predetermined sea area A first ultrasonic receiver serving as a reference provided below the sea surface of the marine structure and an observation second provided below the sea surface of the floating body are transmitted from the ultrasonic transmitter disposed. Received with an ultrasonic receiver,
The distance between the ultrasonic transmitter and each ultrasonic receiver is determined based on the propagation time from the transmission of the ultrasonic wave transmitted from the ultrasonic transmitter to the reception, and the difference between these two distance data. Seeking
High-pass filter processing is performed on the difference between the two distance data obtained above to extract a short period fluctuation component,
The above-mentioned formula is extracted in which each relative displacement amount on the three-dimensional coordinate axis between the two ultrasonic receivers having coefficients of the azimuth angle and the depression angle of the first ultrasonic receiver with respect to the ultrasonic transmitter is an unknown. A ternary linear equation that is equal to the short-period fluctuation component is created for each ultrasonic transmitter, and the ternary simultaneous equation is solved to obtain at least the displacement in the height direction of the short-period fluctuation component. A wave measurement method using ultrasonic waves characterized by obtaining height. A wave measurement system that measures the height of waves in a given sea area by detecting changes in floating bodies suspended and moored on the sea surface.
While being suspended, anchored to the sea surface in a predetermined sea area is larger than the floating first to be provided with reference respectively below has been offshore structures and the floating so as not to be affected by wave than the floating An ultrasonic receiver and a second ultrasonic receiver for observation;
An ultrasonic transmitter disposed at least at three locations on or near the seabed below the offshore structure and floating body;
Waves that measure the wave height by determining the distance between the ultrasonic transmitter and each ultrasonic receiver based on the propagation time from the transmission of the ultrasonic wave transmitted from the ultrasonic transmitter to reception. A measuring device,
The above wave measuring device
A distance calculation unit for determining a distance between the ultrasonic transmitter and each ultrasonic receiver based on a propagation time from transmission of the ultrasonic wave transmitted from the ultrasonic transmitter to reception thereof, and the distance calculation unit A difference calculation unit for obtaining a difference between the two distance data obtained in step 1, a short cycle fluctuation component extracting unit for extracting a short cycle fluctuation component by performing a high-pass filter process on the difference between the two distance data obtained by the difference calculation unit, and The above-mentioned formula is extracted in which each relative displacement amount on the three-dimensional coordinate axis between the two ultrasonic receivers having coefficients of the azimuth angle and the depression angle of the first ultrasonic receiver with respect to the ultrasonic transmitter is an unknown. A ternary linear equation that is equal to the short-period fluctuation component is created for each ultrasonic transmitter, and the ternary simultaneous equation is solved to obtain at least the displacement in the height direction of the short-period fluctuation component. Wave measurement system using ultrasonic waves, characterized by being configured from a short cycle fluctuation component calculation section for obtaining a of. A wave measurement method for measuring the height of a wave in a predetermined sea area by detecting a change in a floating body suspended or moored on the sea surface,
While being suspended, anchored to the sea surface in a predetermined sea area is larger than the floating first be provided with reference respectively under sea surface has been offshore structures and the floating so as not to be affected by wave than the floating An ultrasonic wave is transmitted into the sea from one ultrasonic transmitter / receiver and a second ultrasonic transmitter / receiver for observation, and the ultrasonic waves from the wave repeaters arranged at least at three locations near or below the bottom of the sea Received with an ultrasonic transceiver,
The distance between the ultrasonic repeater and each ultrasonic transmitter / receiver is determined based on the round-trip propagation time from the transmission of the ultrasonic wave transmitted from the ultrasonic transmitter / receiver to the reception thereof, and the difference between these two distance data Seeking
High-pass filter processing is performed on the difference between the two distance data obtained above to extract a short period fluctuation component,
An expression in which the relative displacements on the three-dimensional coordinate axis between the two ultrasonic receivers with the coefficients of the azimuth angle and the depression angle of the first ultrasonic transmitter / receiver as a coefficient is an unknown is extracted. Create a ternary linear equation equal to the periodic fluctuation component for each sonic repeater, and solve this ternary linear equation to obtain at least the displacement in the height direction of the short periodic fluctuation component to determine the wave height A method of measuring waves using ultrasonic waves, characterized in that A wave measurement system that measures the height of waves in a given sea area by detecting changes in floating bodies suspended and moored on the sea surface.
While being suspended, anchored to the sea surface in a predetermined sea area is larger than the floating first to be provided with reference respectively below has been offshore structures and the floating so as not to be affected by wave than the floating An ultrasonic transceiver and a second ultrasonic transceiver for observation;
Acoustic repeaters disposed at least at three locations on or near the bottom of the ocean structure and floating body;
Waves for measuring the wave height by determining the distance between the sound wave repeater and each of the ultrasonic wave transmitters / receivers based on the round-trip propagation time from transmission of the ultrasonic wave transmitted from the ultrasonic wave transmitter / receiver to reception. A measuring device,
The above wave measuring device
A distance calculation unit for determining a distance between the sound wave repeater and each of the ultrasonic transmitters / receivers based on a round-trip propagation time from transmission of the ultrasonic wave transmitted from the ultrasonic transmitter / receiver to reception thereof, and the distance calculation unit The difference calculation unit for calculating the difference between the two distance data obtained in step 1, and the short cycle fluctuation component extracting unit for extracting the short period fluctuation component by performing high-pass filter processing on the difference between the two distance data obtained by the difference calculation unit. , And the above-mentioned formulas using the relative displacements on the three-dimensional coordinate axis between the two ultrasonic receivers with the azimuth angle and the depression angle of the first ultrasonic transmitter / receiver as the coefficients relative to the sound wave repeater as the coefficients are extracted as described above. A ternary linear equation that is equal to the short-period fluctuation component is created for each sonic repeater, and at least the height of the short-period fluctuation component is solved by solving the ternary simultaneous equation. Wave measurement system using ultrasonic waves, characterized in that the displacement of seeking consist of short-period fluctuation component calculation section for obtaining the wave height. A wave measurement method for measuring the height of a wave in a predetermined sea area by detecting a change in a floating body suspended or moored on the sea surface,
While being suspended, anchored to the sea surface in a predetermined sea area is larger than the floating first be provided with reference respectively under sea surface has been offshore structures and the floating so as not to be affected by wave than the floating Sending ultrasonic waves into the sea from 1 ultrasonic transceiver and 2nd ultrasonic transceiver for observation,
The ultrasonic waves and relay times relayed by the ultrasonic wave relays arranged at least at three locations on the seabed or near the seabed below these ultrasonic wave transceivers are received by the ultrasonic wave transmitters and received from the ultrasonic wave relays. The distance between the sonic repeater and each ultrasonic transmitter / receiver is determined based on the propagation time of each, and the difference between these two distance data is determined,
High-pass filter processing is performed on the difference between the two distance data obtained above to extract a short period fluctuation component,
An expression in which the relative displacements on the three-dimensional coordinate axis between the two ultrasonic receivers with the coefficients of the azimuth angle and the depression angle of the first ultrasonic transmitter / receiver as a coefficient is an unknown is extracted. Create a ternary linear equation equal to the periodic fluctuation component for each sonic repeater, and solve this ternary linear equation to obtain at least the displacement in the height direction of the short periodic fluctuation component to determine the wave height A method of measuring waves using ultrasonic waves, characterized in that A wave measurement system that measures the height of waves in a given sea area by detecting changes in floating bodies suspended and moored on the sea surface.
A marine structure that is floated and moored on the surface of a predetermined sea area and is larger than the floating body so that it is less affected by waves than the floating body. An ultrasonic transceiver and a second ultrasonic transceiver for observation;
A sonic repeater that is disposed at least at three locations on the seabed or near the seafloor below the offshore structure and floating body and relays the ultrasonic waves from the ultrasonic transceiver to transmit the ultrasonic waves and the relay time together;
Wave measurement that measures the wave height by determining the distance between each of the sound wave repeaters and each of the ultrasonic wave transmitters / receivers based on the propagation time from transmission of the ultrasonic wave transmitted from the sound wave repeater to reception. A device,
The above wave measuring device
A distance calculator that receives the ultrasonic wave transmitted from the sonic repeater and the relay time and obtains a distance between the sonic repeater and each ultrasonic transceiver based on a propagation time from the sonic repeater; A difference calculation unit that calculates the difference between the two distance data obtained by the distance calculation unit, and a short-cycle fluctuation component that is extracted by performing high-pass filter processing on the difference between the two distance data obtained by the difference calculation unit. An expression in which each relative displacement amount on the three-dimensional coordinate axis between the two ultrasonic receivers with coefficients of the azimuth angle and the depression angle with respect to the sound wave repeater of the periodic fluctuation component extraction unit and the first ultrasonic transmitter / receiver is an unknown Is created for each sonic repeater so as to be equal to the extracted short-period fluctuation component, and at least a short-period fluctuation component is solved by solving this ternary simultaneous equation. Wave measurement system using ultrasonic waves, characterized by being configured from a short cycle fluctuation component calculation section for obtaining a wave height seeking of the height direction displacement.

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